FreeBSD VuXML: Documenting security issues in FreeBSD and the FreeBSD Ports Collection

tarsnap -- buffer overflow and local DoS

Affected packages
tarsnap < 1.0.36


VuXML ID 2fe40238-480f-11e5-adde-14dae9d210b8
Discovery 2015-08-21
Entry 2015-08-21

Colin Percival reports:

1. SECURITY FIX: When constructing paths of objects being archived, a buffer could overflow by one byte upon encountering 1024, 2048, 4096, etc. byte paths. Theoretically this could be exploited by an unprivileged user whose files are being archived; I do not believe it is exploitable in practice, but I am offering a $1000 bounty for the first person who can prove me wrong:

2. SECURITY FIX: An attacker with a machine's write keys, or with read keys and control of the tarsnap service, could make tarsnap allocate a large amount of memory upon listing archives or reading an archive the attacker created; on 32-bit machines, tarsnap can be caused to crash under the aforementioned conditions.